Felbamate and Norethindrone and ethinyl estradiol interaction
Felbamate and Norethindrone and ethinyl estradiol: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Felbamate (Felbatol) label · effective 2025-08-15
Effects of Felbatol ® on Low-Dose Combination Oral Contraceptives A group of 24 nonsmoking, healthy white female volunteers established on an oral contraceptive regimen containing 30 µg ethinyl estradiol and 75 µg gestodene for at least 3 months received 2400 mg/day of felbamate from midcycle (day 15) to midcycle (day 14) of two consecutive oral contraceptive…
Felbamate treatment resulted in a 42% decrease in the gestodene AUC 0-24, but no clinically relevant effect was observed on the pharmacokinetic parameters of ethinyl estradiol.
From the Norethindrone and ethinyl estradiol (Lo Loestrin Fe) label · effective 2025-03-07
Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include: barbiturates bosentan carbamazepine felbamate griseofulvin oxcarbazepine phenytoin rifampin St.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.